Rotary agitator with reverse helix pattern

ABSTRACT

A rotary agitator for a cleaning apparatus includes a cylindrical body and a projecting cleaning element carried on that cylindrical body. The projecting cleaning element has a chevron shape and includes a first, outwardly directed face and a second, inwardly directed face. The first outwardly directed face defines a leading edge during agitator rotation whereby nap of an underlying carpet being cleaned is pushed outwardly toward opposing ends of the cylindrical body. Accordingly, dirt at the base of the nap is exposed to the airstream and better, deep cleaning efficiency is provided.

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/610,375 filed on 16 Sep. 2004.

TECHNICAL FIELD

The present invention relates generally to the floor care equipment field and, more particularly, to a rotary agitator with a reverse helix pattern, a floor care appliance equipped with such a rotary agitator and to a method of deep cleaning a carpet or rug.

BACKGROUND OF THE INVENTION

A vacuum cleaner is an electrically powered, mechanical appliance utilized for the dry removal of dust and loose dirt from carpets, rugs, fabrics and other surfaces. Vacuum cleaners have been widely utilized for years in domestic and industrial cleaning applications.

In operation, a pressure drop is utilized to force air entrained with loose dirt and dust into the nozzle of the vacuum cleaner. The dust and dirt laden air is then drawn through a bag or dirt cup which traps and retains the dirt. The air is then exhausted by electric fan through an additional filter to remove relatively fine particles. It is this fan that provides the air pressure drop or vacuum that provides the cleaning action.

Airflow velocity and placement are the key parameters in determining the cleaning efficiency provided by the air drawn into the vacuum cleaner. A standard floor nozzle S for an upright or canister vacuum cleaner draws air under its entire perimeter and across its relatively large footprint area (see prior art vacuum cleaner illustrated in FIG. 1). Airflow velocity increases gradually toward the mouth of the suction tube or inlet port T, where it is maximized. Moreover, air, as a flow medium, follows the path of least resistance, and beyond the lower edge of the nozzle, will travel across the upper surface of the carpet. Hence, embedded residue is unaffected by airflow alone and deep carpet cleanability must rely almost exclusively on agitator performance.

In the past, rotary agitators A have often included cooperating cleaning elements or ribs R of helix design. As the agitator rotates in the direction of action arrows B, such ribs tend to press the nap N and carpet fibers down and toward the middle of the rotary agitator toward the mouth of the suction tube T (see action arrows W in FIGS. 2 a and 2 b). Consequently, loose dirt and debris in the upper portions of the carpet nap are swept by the cleaning elements over the surface of the carpet toward the suction tube T. However, it should be appreciated that deep, ground-in dirt and debris toward the bottom of the carpet nap underlying the center of the agitator is covered over by the outer nap being pressed down toward the middle of the agitator. This action places the carpet fibers in a position directly between embedded dirt at the base of the nap and the suction tube T, to impede airflow and the lifting of the dirt and debris from deep down in the carpet. As a result, cleaning efficiency is detrimentally impacted and dirt and debris deep down in the nap tends to stay there.

The present invention addresses this problem by providing a suction inlet port or tube centrally located within the nozzle, and an agitator that brushes carpet nap outwardly toward the ends of the agitator thereby exposing the base of the nap and any loosened dirt and debris to enhance airflow for lifting that dirt and debris therefrom and increasing deep cleaning efficiency.

SUMMARY OF THE INVENTION

In accordance with the purposes of the present invention as described herein, a rotary agitator is provided that is particularly adapted to provide high efficiency deep cleaning. The rotary agitator includes a cylindrical body and a projecting cleaning element or rib carried on that cylindrical body. The projecting cleaning element has a chevron shape and includes a first, outwardly directed face and a second, inwardly directed face. The first outwardly directed face defines a leading edge during agitator rotation whereby the nap of an underlying carpet being cleaned is pushed outwardly toward opposing ends of the cylindrical body.

More specifically describing the invention the cleaning element includes an apex adjacent a midline of the cylindrical body. Further the projecting cleaning element may be interrupted. The interruption in the element is provided at the apex. The element may include a brush or one or more bristle tufts.

In accordance with an additional aspect of the present invention the rotary agitator comprises a cylindrical body having a midline, a first end, a second end, a rotational axis and a direction of rotation about the rotational axis. Additionally, the rotary agitator includes a first projecting cleaning element extending from a first point adjacent the midline of the cylindrical body toward the first end of the cylindrical body in the direction of rotation. Additionally, the rotary agitator includes a second projecting cleaning element extending from a second point adjacent the midline of the cylindrical body toward the second end of the cylindrical body in the direction of rotation. During rotation of the agitator the nap of an underlying carpet being cleaned is pushed outwardly toward the first and second ends of the cylindrical body thereby opening the nap of the carpet to the direct suction airflow of the centrally located suction inlet port in order to allow more efficient deep cleaning action.

In accordance with additional aspects of the present invention the first projecting cleaning element may be interrupted. Similarly, the second projecting cleaning element may be interrupted. In one possible embodiment at least one of the projecting cleaning elements includes a brush. In another at least one of the projecting cleaning elements includes a bristle tuft.

In accordance with still another aspect of the present invention a method is provided for cleaning the nap of a rug or carpet utilizing a rotary agitator. That method comprises the step of rotating the rotary agitator and brushing the nap outwardly toward opposed ends of the rotary agitator. As noted above this serves to open the nap of the underlying carpet being cleaned to the direct line of suction airflow from the centrally located suction inlet port so the dirt and debris may be drawn efficiently from the base of the nap utilizing this suction airflow.

In the following description there is shown and described several possible embodiments of the invention, simply by way of illustration of some of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments, and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of the specification, illustrate several aspects of the present invention, and together with the description serve to explain certain principles of the invention. In the drawings:

FIG. 1 is a schematical view showing airflow produced by a standard floor nozzle of prior art design;

FIGS. 2 a and 2 b are schematical views illustrating how helical cleaning ribs on rotary agitators of prior art design tend to brush the nap of a carpet toward the middle of the agitator and the suction tube or inlet port;

FIG. 3 is a perspective view of one possible embodiment of an upright vacuum cleaner incorporating the rotary agitator of the present invention;

FIGS. 4 a and 4 b are schematical representations illustrating how the rotary agitator of the present invention functions to push the nap of an underlying carpet outwardly toward the opposing ends of the cylindrical body so as to expose the base of the nap to the airstream being drawn through the centrally located suction inlet port into the vacuum cleaner;

FIG. 5 is a rear perspective view showing an alternative embodiment of the present invention wherein the projecting cleaning elements are formed by bristle tufts; and

FIG. 6 is still another alternative embodiment of the present invention wherein the projecting cleaning elements are formed by a plurality of individual bristles or a continuous bar or rib.

Reference will now be made in detail to the illustrated embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference is now made to FIG. 3 illustrating an upright vacuum cleaner 10 incorporating the rotary agitator 20 of the present invention. It should be noted that this is just one possible embodiment of the floor care appliance of the present invention and that other possible embodiments include but are not limited to canister vacuum cleaners, handheld vacuum cleaners and extractors.

The vacuum cleaner 10 includes a housing, generally designated by reference numeral 12, including a nozzle assembly 14 and a handle assembly 16. As is known in the art, the handle assembly 16 is pivotally connected to the nozzle assembly 14 to aid the operator in manipulating the vacuum cleaner 10 back and forth across the floor. Wheels (not shown) carried on the housing 12 or nozzle assembly 14 allow the vacuum cleaner 10 to be moved smoothly across the floor. As illustrated, the nozzle assembly 14 is equipped with a nozzle inlet 18. The rotary agitator 20 is mounted for rotation on the nozzle assembly 14 across the nozzle inlet 18.

The handle assembly 16 houses a suction generator 22 (i.e. a fan and motor assembly) and a dirt collector 24 having an internal dirt collection chamber. The dirt collector 24 is illustrated as a cylindrical dirt cup which when equipped with a tangentially directed opening will produce a cyclonic flow of air for enhanced cleaning efficiency in accordance with principles well known in the art. The dirt cup may or may not be equipped with an internal filter. The dirt collector 24 may also comprise a filtration bag. The handle assembly 16 also includes a control stalk 28 and an actuator switch 26 for turning the vacuum cleaner 10 on and off and thereby driving the rotary agitator 20 and the suction generator 22.

The agitator 20 is shown in detail in FIGS. 4 a and 4 b. The agitator 20 comprises a cylindrical body 30 carrying a projecting cleaning element, generally designated by reference numeral 32. The projecting cleaning element 32 includes an opening or apex 34 adjacent a midline M of the cylindrical body 30. As illustrated the apex 34 and midline M are aligned with and underlie the suction inlet port 36 on the nozzle assembly 14 through which the suction generator 22 draws an airstream with entrained dirt and debris into the vacuum cleaner 10. In the embodiment illustrated in FIGS. 4 a and 4 b, an interruption is provided in the projecting cleaning element 32 at the apex 34. Accordingly, the projecting cleaning element 32 may be said to comprise two cleaning element segments 38 and 40.

The first segment 38 extends from a first point adjacent the midline M of the cylindrical body 30 toward the first end 42 of the cylindrical body. The second segment 40 extends from a second point adjacent the midline M of the cylindrical body 30 toward the second end 44 of the cylindrical body. As illustrated the overall projecting cleaning element 32 is of substantially chevron shape while the individual segments 38, 40 are both substantially helical in shape.

The projecting cleaning element 32 and the individual segments 38, 40 include a first, outwardly directed face 46 and a second inwardly directed face 48. In operation the agitator 20 is rotated in the direction of action arrows C. Accordingly, the first outwardly directed face 46 defines a leading edge during agitator rotation whereby nap of an underlying carpet being cleaned is pushed outwardly toward opposing ends 42, 44 of the cylindrical body 30 (see illustration of nap N in FIGS. 4 a and 4 b).

As illustrated, the agitator 20 functions to brush the nap N outwardly (see action arrows Y), away from the suction inlet port 36 so as to expose the base of the nap directly to the airstream being drawn into the suction inlet port. Accordingly, loosened dirt and debris at the base of the nap is freely drawn into the vacuum cleaner 10 and deep cleaning efficiency is significantly enhanced. This can easily be appreciated when one compares the positioning of the nap N produced by the operation of the agitator 20 of the present invention as illustrated in FIG. 4 b with the positioning of the nap N produced by operation of a prior art agitator as illustrated in FIG. 2 b. As shown, the nap N in FIG. 2 b is brushed toward the center of the agitator and dirt and debris at the base of the nap is covered over by the nap which effectively blocks the airstream and hinders deep cleaning. Thus, the nap N actually prevents efficient and effective deep cleaning as it is brushed by a prior art agitator.

In the embodiment illustrated in FIGS. 4 a and 4 b, the projecting cleaning element 32 and, therefore, the first and second segments 38, 40 are illustrated as a rib, beater bar or wiper. In the embodiment illustrated in FIG. 5, the projecting cleaning element 32 and segments 38, 40 are formed by a series of bristle tufts 50 (i.e. the cleaning element includes multiple interruptions). In the embodiment of the present invention illustrated in FIG. 6, the projecting cleaning element 32 and first and second segments 38, 40 are formed by a brush or a continuous wall of bristles (or a continuous rib, beater bar or wiper).

The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. For example, while the illustrated embodiment is an upright vacuum cleaner 10, the present invention also relates to and includes canister and handheld vacuum cleaners as well as extractors. Further, while the illustrated embodiment is a “clean air” system with a suction generator 22 downstream from the dirt collector 24, the present invention also includes “dirty air” systems where the suction generator is located upstream of the dirt collector.

Further, it should be appreciated that the dirt collector may take the form of a disposable filter bag or a dirt cup either of which may take advantage of structures providing for cyclonic airflow if desired. Further, while the illustrated vacuum cleaner 10 includes one rotary agitator 20, it could include two or more rotary agitators if desired. Further, where a vacuum cleaner or floor care appliance is equipped with multiple suction tubes or inlet ports, the agitator 20 may be equipped with a cleaning element formed with multiple chevrons or apexes so that the nap is brushed away from each such inlet port as the agitator is driven. Finally, at least one of the projecting cleaning elements may include at least one air intake aperture for drawing air, dirt and debris into the cylindrical body of the agitator such as described in copending U.S. patent application Ser. No. 60/604,392 filed on 25 Aug. 2004 and fully incorporated herein by reference.

The embodiments were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled. The drawings and preferred embodiments do not and are not intended to limit the ordinary meaning of the claims and their fair and broad interpretation in any way. 

1. A rotary agitator for a cleaning apparatus, comprising: a cylindrical body; and a projecting cleaning element carried on said cylindrical body, said projecting cleaning element having a chevron shape and including a first, outwardly directed face and a second, inwardly directed face, said first, outwardly directed face defining a leading edge during agitator rotation whereby nap of an underlying carpet being cleaned is pushed outwardly toward opposing ends of said cylindrical body.
 2. The rotary agitator of claim 1 wherein said projecting cleaning element includes an apex adjacent a midline of said cylindrical body.
 3. The rotary agitator of claim 2, wherein said projecting cleaning element is interrupted.
 4. The rotary agitator of claim 3, wherein an interruption in said projecting cleaning element is provided at said apex.
 5. The rotary agitator of claim 1, wherein said projecting cleaning element includes a wall of bristles.
 6. The rotary agitator of claim 1, wherein said projecting cleaning element includes at least one bristle tuft.
 7. The rotary agitator of claim 1, wherein said projecting cleaning element is selected from a group of structures consisting of a smooth and continuous rib, beater bar, wiper or a series thereof.
 8. A rotary agitator, comprising: a cylindrical body having a midline, a first end, a second end, a rotational axis and a direction of rotation about said rotational axis; a first projecting cleaning element extending from a first point adjacent said midline of said cylindrical body toward said first end of said cylindrical body in said direction of rotation; and a second projecting cleaning element extending from a second point adjacent said midline of said cylindrical body toward said second end of said cylindrical body in said direction of rotation; whereby nap of an underlying carpet being cleaned is pushed outwardly toward said first and second ends of said cylindrical body.
 9. The rotary agitator of claim 8 wherein said first projecting cleaning element is interrupted.
 10. The rotary agitator of claim 9, wherein said second projecting cleaning element is interrupted.
 11. The rotary agitator of claim 8, wherein at least one of said first projecting cleaning element and said second projecting cleaning element includes a wall of bristles.
 12. The rotary agitator of claim 8, wherein at least one of said first projecting cleaning element and said second projecting cleaning element includes at least one bristle tuft.
 13. The rotary agitator of claim 8, wherein said projecting cleaning element is selected from a group of structures consisting of a smooth and continuous rib, beater bar, wiper or a series thereof.
 14. A method of cleaning nap of a rug or carpet utilizing a rotary agitator, comprising: rotating said rotary agitator and brushing said nap outwardly toward opposing ends of said rotary agitator.
 15. A method of cleaning nap of a rug or carpet with a floor care appliance, comprising: providing a suction inlet port and suction generator for drawing dirt and debris from a rug or carpet into said floor care appliance; brushing said nap of said carpet away from said suction inlet port so as to expose a base of said nap to an airstream being drawn into said suction inlet port.
 16. A floor care appliance, comprising: a housing; a suction generator carried on said housing; a dirt collection vessel carried on said housing; a rotary agitator carried on said housing, said rotary agitator being characterized by a cylindrical body and a projecting cleaning element carried on said cylindrical body, said projecting cleaning element having a chevron shape and including a first, outwardly directed face and a second, inwardly directed face, said first, outwardly directed face defining a leading edge during agitator rotation whereby nap of an underlying carpet being cleaned is pushed outwardly toward opposing ends of said cylindrical body.
 17. A floor care appliance, comprising: a housing; a suction generator carried on said housing; a dirt collection vessel carried on said housing; a suction inlet port carried on said housing and provided in fluid communication with said suction generator; an agitator carried on said housing, said agitator including a nap engaging projection having an opening therein substantially aligned with said suction inlet port and a leading edge diverging from said suction inlet port for displacing nap of an underlying carpet away from said suction inlet port. 